1. Field of the Invention
The present invention relates to a freezing device for supercooled water to be incorporated into an ice-based heat accumulating unit of a freezer for resolving the supercooled state of liquid water by freezing it, particularly to a freezing device whereby it is possible to actively freeze supercooled water of low supercool level at any desired time and at any desired place.
2. Prior Art
A known prior technique for resolving (freezing) the supercooled state of liquid water consists of allowing a flow of supercooled water to freely fall onto a plate to make the water freeze there.
However, with this technique, supercooled water will require a sufficiently long distance to fall through for its secure freezing, which will lead to enlargement of the necessary unit. Moreover, with this technique, it is impossible to actively interfere with the supercooled state of water to make the water freeze at a desired time and place, nor to freeze the supercooled water if its supercooled state is at a low level.
To meet such flaws inherent to the prior art, the present invention aims at providing a freezing device being small in size, and capable of so actively interfering with the supercooled state of liquid water as to freeze it rapidly at any desired time and place, even if the supercooled state is at such a low level as to be resistive to freezing.
The freezing device for supercooled water provided by this invention to serve as an effective solution of above problems comprises a cylinder to receive supercooled water; at least one piston to fit liquid-tight to the cylinder to move therein, which, by moving through the cylinder, introduces supercooled water into the cylinder, gives a mechanical impact to the supercooled water, thereby resolving the supercooled state of the water, and expels water in which the supercooled state has been resolved from the cylinder; and a water inlet and outlet to be provided on at least one of the cylinder and piston in such a way as to allow their opening and closure at a desired timing. The water inlet and outlet may be substituted for a passage which serves both as an inlet and outlet.
The freezing device operates as follows: the cylinder is immersed in supercooled water; the water inlet is opened and the piston is moved in a predetermined direction, to introduce supercooled water into the cylinder until the water fills the latter; after the water inlet has been closed, the piston is instantly moved towards the supercooled water, to give an impact against the latter; and the supercooled state of water is interfered therewith, and part of water is solidified to form nuclei for freezing. Later, the water outlet is opened; the piston is moved in a direction opposite to the above predetermined direction; and water whose supercooled state has been resolved is expelled into bulk supercooled water outside the cylinder to freeze the bulk supercooled water in a successive manner.
Accordingly, the freezing device of this invention, even though it may be reduced in size as compared to a previous similar device, can interfere so actively with the supercooled state of liquid water which is considerably resistive to freezing, that it freezes the latter instantly at any desired time. Because of its comparatively small size, it is possible to prepare many of the devices to arrange them in supercooled water, or to move the device from one place to another, and thus to freeze supercooled water at any desired place.
Thus, if the freezing device of this invention is incorporated in an ice-based heat accumulating system to serve as a supercooled state resolving device, it will be possible to greatly reduce the freezing load of the freezer, which will in turn contribute to saving of energy, effective use of a freezer or air-conditioner, and protection of the environment.
With the freezing device of this invention, the cylinder may have a water inlet and outlet formed thereon, and include two pistons, of which one opens/closes the water inlet and outlet, while the other introduces supercooled water into the cylinder, gives an impact against the water filling the cylinder, and expels the water whose supercooled state has been resolved outside the cylinder.
The above freezing device has two pistons, one for opening/closing the water inlet and outlet and the other for introducing supercooled water into the cylinder and giving an impact against the water; after supercooled water has been introduced into the cylinder, one piston closes the water inlet and outlet to seal the cylinder, and the other piston is pulled apart from the supercooled water in the cylinder; air in the supercooled water within the cylinder is subjected to expansion under reduced pressure to form an accumulation of air having a negative pressure in the cylinder; the piston continues to retreat in the face of an elastic counter pull caused by the negative pressure of air; at this state the pull to the piston is released momentarily; the piston is moved forcibly at a high speed by the counter pull towards the supercooled water (to compress the air); and the piston bumps against the surface of supercooled water to give an impact to the latter.
Hence, it is possible for the above device to give a hard impact against supercooled water in the cylinder through the piston, although it is simple in structure.
The freezing device of this invention may have a heater around the cylinder. Such a freezer device can heat the cylinder with the heater while water whose supercooled state has been resolved in the presence of an impact from the piston is being discharged from the cylinder. This prevents adhesion of ice-crystal nuclei to the inner wall of the cylinder without overheating of supercooled water adjacent to the cylinder, and thus ensures continuous operation of the freezer device in question.